(a) Field of the Invention
The present invention is related to a cooling fan dust guard, and more particularly, to one that prevents the airflow carrying dust an easy ingression and even keeps off the flying dust from entering into the spindle.
(b) Description of the Prior Art
A cooling fan is usually adapted to a motor. Though providing simple function, the cooling fan plays a very important role in cooling for the entire system. Upon starting the machine, the cooling fan is required to maintain long term operation. Since the cooling fan is essentially working on the spindle and the bearing that are two relatively mobile parts in the system, extra care is required for the interface between said two parts, which must be kept properly lubricated and without ingression of foreign matters to warrant longer service life for the cooling fan.
As illustrated in FIG. 1, a cooling fan of the prior art is essentially comprised of a fan blade unit (a) integrated with a stator coil unit (b), a circuit board (c) and a frame (d). Wherein, a spindle (a1) from the center of the fan blade unit (a) passes through a bearing (b1) at the center of the stator coil (b) to constitute a cooling fan as illustrated in FIG. 2. When the cooling fan rotates, the spindle (a1) engages in motion relatively to that of the bearing (b1). However, under long-term dynamic operation, the cooling fan is vulnerable to permit ingression the airflow carrying dust to fall on the gap between the spindle (a1) and the bearing (b1) to damage lubricity of the spindle (1a), then the spindle (1a) becomes slower, creates higher level of noise, and in serious case, and rendered inoperative due to jammed axis of the blade.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
primary purpose of the present invention is to provide a cooling fan dust structure that prevents easy ingression of airflow carrying dust, and even keeps off the flying dust from falling on the spindle when the unit of fan blade is rotating. To achieve the purpose, a rib and a recess are provided on the inner side of the fan blade to create an overcut height difference with the opening of a bushing.
The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.